In this file photo, UCLA quarterback Brett Hundley passes against New Mexico State during the first half of their college football game in the Rose Bowl in Pasadena, Calif., on Saturday, Sept. 21, 2013. (Keith Birmingham Pasadena Star-News file)

Several factors will determine how good UCLA’s offense will be, from its deeper offensive line to a healthy group of running backs.

But more than anything else, the Bruins need Brett Hundley to be great.

After already setting numerous school records, the quarterback turned down entry to the NFL draft, took out a reported $10 million insurance policy and is staying in Westwood for a chance at a national championship.

Hundley has all the tools to be a great pro: a 6-foot-3, 230-pound frame with 10 percent body fat; good pocket presence and a strong arm; and enough athleticism and instincts to save broken plays.

But he still isn’t a finished product, and at times last season, he struggled through bouts of poor decision-making. The good news is that of the nine interceptions he threw, only one came in the last six games.

He’ll have plenty of tools around him, even if — outside of part-time running back Myles Jack — the Bruins don’t possess another All-American playmaker that makes opposing defensive coordinators lose sleep.

Leading receiver Shaq Evans graduated and became a fourth-round draft pick, but the Bruins return full-time starters Devin Fuller and Jordan Payton, as well as an athletic pass-catcher in Devin Lucien. The biggest breakout candidate is likely inside receiver Thomas Duarte, a smooth-running target who tied UCLA’s freshman record last season with three touchdown catches.

The running back carousel looks nearly identical to last season’s iteration, save that everyone appears to be fully healthy. Penciled in as the starter is senior Jordon James, a seasoned pass blocker who also ran for 424 yards in three games last season before injuring his ankle. Behind him are sophomore Paul Perkins and junior Steve Manfro, and freshmen Adarius Pickett or Nathan Starks could also pop in for carries.

And of course, there’s the offensive line. So often last season, a unit that ended up starting three true freshmen became the focal point whenever UCLA struggled to score. That shouldn’t be the case anymore, as long as everyone can stay healthy.

All-American guard Xavier Su’a-Filo left for the pros, but nearly every other significant piece returns with more experience. Graduate transfer Malcolm Bunche came from Miami and will likely start at left tackle, though he can also elsewhere if necessary. True freshman NaJee Toran enrolled early and could be a physical presence at guard.